1. Field of the Invention
The present invention relates to a method for starting an electropneumatically actuated wet settling machine for the separation of mineral mixtures, whose separating liquid carries out a pulsation movement which is set in motion by the introduction of compressed air into excitation chambers and exhaust of the air from the excitation chambers by way of inlet and outlet valves, respectively.
2. Description of the Prior Art
The starting of the pulsating movement of the separating liquid in wet settling machines heretofore occurred in practical operation such that air was admitted through the inlet valves and exhausted through the outlet valves, to and from the excitation chambers of the machine in correspondence with the rhythm or cycle of the settling movements. As is well known to those skilled in the art, the air displaces the water with amplitudes which slowly increase, the settling liquid, normally water, being located in the excitation chambers, and thus sets the pulsation movement in operation. Particularly with large machines, in which appreciable quantities of water are displaced and must be set in motion, the known starting operation, however, proceeds in an unsatisfactory manner in which starting takes too long, or particularly with a large quantity of material on the settling bed, the pulsation cannot be set in motion.
As is disclosed in the German published application 25 27 756.9, a starting method for wet settling machines is known in the art which ovecomes the foregoing defect. With this method, before the starting of the settling machine, the work chambers are first filled by means of control commands of the operators, first with displacement air of constant pressure, which presses the water out of the displacement chambers. The displacement air is then released through the outlet valves from the excitation chambers, and thus initiates a first downward stroke of the machine, with which the normal pulsation movement may be initiated. As a rule, this method operates satisfactorily with sufficient attention of the operators. It is unsatisfactory that, by means of a special control command, the filling of the excitation chambers with air must precede the actual starting operation, and that each settling chamber must be provided with an air feed having a control valve.